Electrochemical cells, such as fuel cells and lithium-ion batteries, are known. Depending on the operating conditions, each type of cell places a particular set of requirements upon the electrolytes used in them. For fuel cells, this is typically dictated by the type of fuel, such as hydrogen or methanol, used to power the cell and the composition of the membrane used to separate the electrodes. Polymer electrolyte membrane fuel cells, powered by hydrogen as the fuel, could be run at higher operating temperatures than currently employed to take advantage of lower purity feed streams, improved electrode kinetics, and better heat transfer from the fuel cell stack to improve its cooling. Waste heat could also be employed in a useful fashion. However, if current fuel cells are to be operated at greater than 100° C. then they must be pressurized to maintain adequate hydration of typical polymer electrolyte membranes, such DuPont Nafibn® perfluorosulfonic acid membrane, to support useful levels of proton conductivity.
There is an ongoing need to discover novel electrolytes that improve the performance of the latest generation of electrochemical cells, such as fuel cells and lithium-ion batteries. For high-temperature fuel cells, this can be addressed by developing new polymer electrolyte membrane materials that maintain adequate proton conductivity at lower levels of hydration.